Microbiome analyses of blood and tissues suggest cancer diagnostic approach.

Systematic characterization of the cancer microbiome provides the opportunity to develop techniques that exploit non-human, microorganism-derived molecules in the diagnosis of a major human disease. Following recent demonstrations that some types of cancer show substantial microbial contributions1-10, we re-examined whole-genome and whole-transcriptome sequencing studies in The Cancer Genome Atlas11 (TCGA) of 33 types of cancer from treatment-naive patients (a total of 18,116 samples) for microbial reads, and found unique microbial signatures in tissue and blood within and between most major types of cancer. These TCGA blood signatures remained predictive when applied to patients with stage Ia-IIc cancer and cancers lacking any genomic alterations currently measured on two commercial-grade cell-free tumour DNA platforms, despite the use of very stringent decontamination analyses that discarded up to 92.3% of total sequence data. In addition, we could discriminate among samples from healthy, cancer-free individuals (n = 69) and those from patients with multiple types of cancer (prostate, lung, and melanoma; 100 samples in total) solely using plasma-derived, cell-free microbial nucleic acids. This potential microbiome-based oncology diagnostic tool warrants further exploration.

Temporal dynamics of the plasma microbiome in recipients at early post-liver transplantation: a retrospective study.

BACKGROUND: Immunosuppression during liver transplantation (LT) enables the prevention and treatment of organ rejection but poses a risk for severe infectious diseases. Immune modulation and antimicrobials affect the plasma microbiome. Thus, determining the impact of immunosuppression on the microbiome may be important to understand immunocompetence, elucidate the source of infection, and predict the risk of infection in LT recipients. We characterized the plasma microbiome of LT recipients at early post-LT and assessed the association between the microbiome and clinical events. RESULTS: In this study, 51 patients who received LT at Nagoya University Hospital from 2016 to 2018 were enrolled. Plasma samples were retrospectively collected at the following time points: 1) within a week after LT; 2) 4 ± 1 weeks after LT; 3) 8 ± 1 weeks after LT; and 4) within 2 days after a positive blood culture. A total of 111 plasma samples were analyzed using shotgun next-generation sequencing (NGS) with the PATHDET pipeline. Relative abundance of Anelloviridae, Nocardiaceae, Microbacteriaceae, and Enterobacteriaceae significantly changed during the postoperative period. Microbiome diversity was higher within a week after LT than that at 8 weeks after LT. Antimicrobials were significantly associated with the microbiome of LT recipients. In addition, the proportion of Enterobacteriaceae was significantly increased and the plasma microbiome diversity was significantly lower in patients with acute cellular rejection (ACR) than non-ACR patients. Sequencing reads of bacteria isolated from blood cultures were predominantly identified by NGS in 8 of 16 samples, and human herpesvirus 6 was detected as a causative pathogen in one recipient with severe clinical condition. CONCLUSIONS: The metagenomic NGS technique has great potential in revealing the plasma microbiome and is useful as a comprehensive diagnostic procedure in clinical settings. Temporal dynamics of specific microorganisms may be used as indirect markers for the determination of immunocompetence and ACR in LT recipients.

Quantitative flow chamber system for evaluating in vitro biofilms and the kinetics of S. aureus biofilm formation in human plasma media.

BACKGROUND: It has been well established that biofilm formation on orthopaedic implants is a critical event in the pathogenesis of orthopaedic infections, yet the natural history of this process with respect to bacterial adhesion, proliferation, and glycocalyx matrix production remains poorly understood. Moreover, there are no quantitative methods yet available to assess the differences in biofilm formation between different bacterial strains or implant materials. Consequently, this study aimed to investigate the natural history of S. aureus in in vitro biofilm formation in human plasma media using a flow chamber system. Bioluminescent S. aureus strains were used to better understand the bacterial growth and biofilm formation on orthopaedic materials. Also, the effects of human plasma media were assessed by loading the chamber with Tryptic Soy Broth with 10% human plasma (TSB + HP). RESULTS: Scanning electron microscopy (SEM) was utilized to assess the morphological appearance of the biofilms, revealing that S. aureus inoculation was required for biofilm formation, and that the phenotypes of biofilm production after 24 h inoculation with three tested strains (SH1000, UAMS-1, and USA300) were markedly different depending on the culture medium. Time course study of the bioluminescence intensity (BLI) and biofilm production on the implants due to the UAMS-1 and USA300 strains revealed different characteristics, whereby UAMS-1 showed increasing BLI and biofilm growth until peaking at 9 h, while USA300 showed a rapid increase in BLI and biofilm formation at 6 h. The kinetics of biofilm formation for both UAMS-1 and USA300 were also supported and confirmed by qRT-PCR analysis of the 16S rRNA gene. Biofilms grown in our flow chamber in the plasma media were also demonstrated to involve an upregulation of the biofilm-forming-related genes icaA, fnbA, and alt. The BLI and SEM results from K-wire experiments revealed that the in vitro growth and biofilm formation by UAMS-1 and USA300 on stainless-steel and titanium surfaces were virtually identical. CONCLUSION: We demonstrated a novel in vitro model for S. aureus biofilm formation with quantitative BLI and SEM outcome measures, and then used this model to demonstrate the presence of strain-specific phenotypes and its potential use to evaluate anti-microbial surfaces.

Fetal mitochondrial DNA in maternal plasma in surrogate pregnancies: Detection and topology.

OBJECTIVES: Due to the maternally-inherited nature of mitochondrial DNA (mtDNA), there is a lack of information regarding fetal mtDNA in the plasma of pregnant women. We aim to explore the presence and topologic forms of circulating fetal and maternal mtDNA molecules in surrogate pregnancies. METHODS: Genotypic differences between fetal and surrogate maternal mtDNA were used to identify the fetal and maternal mtDNA molecules in plasma. Plasma samples were obtained from the surrogate pregnant mothers. Using cleavage-end signatures of BfaI restriction enzyme, linear and circular mtDNA molecules in maternal plasma could be differentiated. RESULTS: Fetal-derived mtDNA molecules were mainly linear (median: 88%; range: 80%-96%), whereas approximately half of the maternal-derived mtDNA molecules were circular (median: 51%; range: 42%-60%). The fetal DNA fraction of linear mtDNA was lower (median absolute difference: 9.8%; range: 1.1%-27%) than that of nuclear DNA (median: 20%; range: 9.7%-35%). The fetal-derived linear mtDNA molecules were shorter than the maternal-derived ones. CONCLUSION: Fetal mtDNA is present in maternal plasma, and consists mainly of linear molecules. Surrogate pregnancies represent a valuable clinical scenario for exploring the biology and potential clinical applications of circulating mtDNA, for example, for pregnancies conceived following mitochondrial replacement therapy.

Plasma pooling in combination with amotosalen/UVA pathogen inactivation to increase standardisation and safety of therapeutic plasma units.

OBJECTIVES: Assessment of the impact of pooling five single-donor plasma (SDP) units to obtain six pathogen-reduced therapeutic plasma (PTP) units on standardisation and the retention of labile coagulation factors. BACKGROUND: SDP shows a high inter-donor variability with potential implications for the clinical treatment outcome. Additionally, there is still an existing risk for window-period transmissions of blood borne pathogens including newly emerging pathogens. METHODS/MATERIALS: Five ABO-identical SDP units were pooled, treated with the INTERTCEPT™ Blood System (Cerus Corporation, U.S.A.) and split into six PTP units which were frozen and thawed after 30 days. The variability in volume, labile coagulation factor retention and activity was assessed. RESULTS: The variability of volumes between the PTP units was reduced by 46% compared to SDP units. The variability in coagulation factor content between the PTP units was reduced by 63% compared to SDP units. Moderate, but significant losses of coagulation factors (except for vWF) were observed in PTPs compared to SDPs. CONCLUSION: The pooling of five SDP units to obtain six PTP units significantly increases product standardisation with potential implications for safety, economics as well as transfusion-transmitted pathogen safety, making it an interesting alternative to quarantine SDP (qSDP) and pathogen-reduced SDP.

Plasma of Acute Lymphoblastic Leukemia Patients React to the Culture of a Mycovirus Containing Aspergillus flavus.

Acute lymphoblastic leukemia (ALL) is the most common cancer in children and is also seen in adults. Currently, no plasma-based test for the detection of ALL is available. We have cultured the home of a patient with ALL and isolated a mycovirus containing Aspergillus flavus. This culture was subjected to electron microscopy, purification, and mass spectrometry. Using enzyme-linked immunosorbent assay technique, plasma of patients with ALL and long-term survivors of this disease were tested for antibodies, utilizing supernatant of the culture of this organism. The results were compared with 3 groups of controls, including healthy individuals, patients with sickle cell disease, and solid tumors. Using electron microscopy, the isolated A. flavus contained mycovirus particles. In chemical analysis, this organism did not produce any aflatoxin. Using an enzyme-linked immunosorbent assay technique, the supernatant of the culture of the mycovirus containing A. flavus could differentiate ALL patients from each group of controls (P<0.001). These studies provide a new technique for the detection of ALL and may add information for future research regarding leukemogenesis.

Cystic Fibrosis Plasma Blunts the Immune Response to Bacterial Infection.

Cystic fibrosis (CF) is caused by mutations of the gene encoding the CF transmembrane conductance regulator. It remains unclear whether the abnormal immune response in CF involves extrinsic signals released from the external or internal environment. We sought to characterize the peripheral immune signatures in CF and its association with clinical phenotypes. Healthy peripheral blood mononuclear cells (PBMCs) were cultured with plasma from CF probands (CFPs) or healthy control subjects (HCs) followed by nCounter gene and microRNA (miRNA) profiling. A discovery cohort of 12 CFPs and 12 HCs and a validation cohort of 103 CFPs and 31 HCs (our previous microarray data [GSE71799]) were analyzed to characterize the composition of cultured immune cells and establish a miRNA‒mRNA network. Cell compositions and miRNA profiles were associated with clinical characteristics of the cohorts. Significantly differentially expressed genes and abundance of myeloid cells were downregulated in PMBCs after culture with CF plasma (P < 0.05). Top-ranked miRNAs that increased in response to CF plasma (adjusted P < 0.05) included miR-155 and miR-146a, which target many immune-related genes, such as IL-8. Pseudomonas aeruginosa infection was negatively associated with abundance of monocytes and the presence of those regulatory miRNAs. Extrinsic signals in plasma from patients with CF led to monocyte inactivation and miRNA upregulation in PBMCs. An improved understanding of the immune effects of extrinsic factors in CF holds great promise for integrating immunomodulatory cell therapies into current treatment strategies in CF.

Impact of probiotics on pathogen survival in an innovative human plasma biofilm model (hpBIOM).

BACKGROUND: Despite of medical advances, the number of patients suffering on non-healing chronic wounds is still increasing. This fact is attended by physical and emotional distress and an economic load. The majority of chronic wounds are infected of harmful microbials in a protecting extracellular matrix. These biofilms inhibit wound healing. Biofilm-growing bacteria developed unique survival properties, which still challenge the appropriate wound therapy. The present in-vitro biofilm models are not suitable for translational research. By means of a novel in-vivo like human plasma biofilm model (hpBIOM), this study systematically analysed the influence of 3 probiotics on the survival of five clinically relevant pathogenic microorganisms. METHODS: Human plasma was used to produce the innovate biofilm. Pathogenic microorganisms were administered to the plasma. By stimulating the production of a fibrin scaffold, stable coagula-like discs with integrated pathogens were produced. The five clinically relevant pathogens P. aeruginosa, S. aureus, S. epidermidis, E. faecium and C. albicans were challenged to the probiotics L. plantarum, B. lactis and S. cerevisiae. The probiotics were administered on top of the biofilm and the survival was quantified after 4 h and 24 h of incubation. For statistics, two-way ANOVA with post-hoc Tukey's HSD test was applied. P-value > 0.05 was considered to be significant. RESULTS: SEM micrographs depicted the pathogens on the surface of the fibrin scaffold, arranged in close proximity and produced the glycocalyx. The application of probiotics induced different growth-reducing capacities towards the pathogens. B. lactis and S. cerevisiae showed slight bacteria-reducing properties. The survival of C. albicans was not affected at all. The most antimicrobial activity was detected after the treatment with L. plantarum. CONCLUSIONS: This study successfully reproduced a novel human biofilm model, which provides a human wound milieu and individual immune competence. The success of bacteriotherapy is dependent on the strain combination, the number of probiotics and the activity of the immune cells. The eradicating effect of L. plantarum on P. aeruginosa should be emphasized.

The imbalance of gut microbiota and its correlation with plasma inflammatory cytokines in pemphigus vulgaris patients.

Pemphigus vulgaris (PV) is an autoimmune disease characterized by the production of IgG autoantibodies owing to an imbalance in the Th1/Th2 and Th17/Tregs cell pathways. The role of gut microbiota in the development of immune system and autoimmune diseases has been unraveled in the last two decades. However, data pertaining to gut microbiota of PV patients is largely lacking. We aimed to compare the gut microbiota of PV patients and healthy controls and assessed potential correlation with circulating cytokines of Th1/Th2/Th17 cell. Faecal bacterial diversity was analysed in 18 PV patients and 14 age- and gender-matched healthy individuals using hypervariable tag sequencing of the V3-V4 region of the 16S rRNA gene. Plasma levels of 20 inflammatory cytokines were assessed using the Luminex screening system. As a result, we identified 10 differentially abundant taxa between patients and controls. At the genera level, Lachnospiracea_incertae_sedis and Coprococcus decreased, while Granulicatella, Flavonifractor enriched in PV. Plasma levels of C5a, interleukin (IL)-2R, IL-6, IL-8, IL-7, IL-1ß, IL17A, IL-5 and IL-21 were significantly increased in PV Flavonifractor exhibited a positive correlation with C5a, IL-6, IL-8, IL-7, IL-1ß, IL17A and IL-21. Lachnospiracea_incertae_sedis and Coprococcus showed a negative correlation with IL-17A. Our results are consistent with the hypothesis that PV patients have gut microbial dysbiosis which might contribute to the immune disorder and the development of PV.

Bacterial survival in whole blood depends on plasma sensitivity and resistance to neutrophil killing.

BACKGROUND: Whole blood (WB) is held at room temperature for not more than 24 hours before blood component manufacturing. The ability of several culture collection, skin-derived, and transfusion-related bacteria to survive in WB stored at 22 ± 2°C for 24 hours was investigated in this study. STUDY DESIGN AND METHODS: Twenty-one bacteria of the species Staphylococcus epidermidis, Staphylococcus aureus, Staphylococcus capitis, Streptococcus agalactiae, Serratia liquefaciens, Serratia marcescens, Klebsiella pneumoniae, Escherichia coli, and Yersinia enterocolitica were inoculated into 7-mL aliquots of WB at a concentration of 500 colony-forming units (CFU)/mL. Spiked WB was stored aerobically at 22 ± 2°C, and bacterial viability and growth were monitored at 3, 8, and 24 hours during WB storage. Bacteria that showed decreased viability during WB incubation were further characterized for their sensitivity to plasma factors and neutrophil killing. RESULTS: There were three different scenarios for bacterial behavior during the hold of WB at 22 ± 2°C. Five bacteria proliferated (p < 0.03), 11 remained viable or showed low proliferation, and a third group of five bacteria had decreased or lost viability (p < 0.01). Three of the latter five bacteria were plasma-sensitive while the other two were plasma-resistant but susceptible to neutrophil killing (p = 0.01). CONCLUSIONS: The bactericidal activity of WB can be the result of plasma sensitivity or neutrophil killing. Bacteria with a starting inoculum of 500 CFU/mL, and able to resist WB immune factors, can proliferate to clinically significant levels posing a potential safety risk to transfusion patients. Results of this pilot study should be validated under standard WB collection and storage conditions.

Pathogen reduced plasma products: a clinical practice scientific review from the AABB.

BACKGROUND: A small body of literature assessing the efficacy and safety of pathogen reduced (PR) plasma has been published. STUDY DESIGN AND METHODS: An AABB committee systematically reviewed the literature and graded the clinical trial evidence with the assistance of a GRADE expert. RESULTS: Most studies identified were low quality and had a small sample size; in addition, efficacy and safety were monitored in many different ways making it difficult to quantify therapeutic benefit and risk. The data analyzed in this systematic review showed that pathogen inactivation did not adversely affect the efficacy of S/D or amotosalen plasma transfusions in any patient population studied. In addition, there were no significant safety issues for these patient populations, other than the specific contraindications noted in their respective package inserts. CONCLUSION: Larger, well-designed trials are needed to further evaluate the efficacy and safety of all of the PR plasma products.

Evaluation of microbial contamination of canine plasma eyedropper bottles following clinical use in canine patients.

OBJECTIVE: To investigate microbial contamination of canine plasma eye drops when used clinically and to compare the effect of two different eyedropper bottles on contamination rate. METHODS: Forty-six bottles containing plasma were randomly dispensed for use on 42 dogs with ulcerative keratitis. Of these, 23 were standard eyedropper bottles and 23 were Novelia® bottles designed to prevent contamination. After use for up to 2 weeks, samples for bacterial culture were obtained from a drop of plasma, the bottle tip, the plasma inside the bottle, and the corneal surface. Fungal culture was performed from a drop of plasma. RESULTS: The overall microbial contamination rate was 17.4% (8/46 bottles); however, only one bottle had growth from the plasma inside the bottle. There was a lower contamination rate of Novelia® bottles (3/23 = 13.0%) compared to standard bottles (5/23 = 21.7%), but this difference was not statistically significant (P = .57). There were also no significant differences in contamination rate of bottles used greater than 7 days compared to less than or equal to 7 days, or in bottles used greater than 4 times daily compared to 4 times daily or less. Three corneal samples (6.5%) had bacterial growth, but none matched contamination from the bottles. CONCLUSIONS: Novelia® bottles may decrease contamination of plasma eye drops used clinically. However, while microbial contamination of plasma bottles was documented, no clinically relevant complications were observed. This study supports safe use of plasma eye drops for up to 2 weeks when refrigerated and dispensed from either Novelia® or standard eyedropper bottles.

Metagenomics in pooled plasma, with identification of potential emerging infectious pathogens.

BACKGROUND: Many emerging infectious pathogens are well known for existing in healthy blood donors and could be transmitted via blood transfusion or plasma derivatives usage. Therefore, there is an urgent need to discover the pathogens in qualified blood donation to avoid potential threats to blood safety. STUDY DESIGN AND METHODS: The objective of this study was to investigate the microbiome that existed in pooled plasma from different manufacturers in Chengdu and Guiyang. Random polymerase chain reaction, large-scale clone sequencing, and bioinformatics were used to investigate the metagenomics and microbiome structure of pooled plasma. Among detected microbiomes, potential pathogens were subsequently identified. RESULT: After host DNA cleaning, 551 clones were classified as bacteria; 88 clones were classified as viruses, and four clones were considered to be parasites, respectively. Thirteen kinds of bacteria and two kinds of parasites that might potentially threaten blood safety were identified along with six kinds of nonpathogenic viruses. The infection status of one identified pathogen Coxiella burnetii was evaluated in 1638 plasma samples. The reactive rate of immunoglobulin (Ig)G1 was 1.10% (18/1638), the reactive rate of IgG2 was 0.85% (14/1638), and the reactive rate of IgM was 0.98% (16/1638). CONCLUSION: Some pathogens that were already considered as threats to blood safety were discovered in those pooled plasma such as C. burnetii, Orientia tsutsugamushi, and Plasmodium sp. As a result, we should initiate some specific tests in the endemic area on plasma donors to enhance the blood safety in China.

Combined effects of spray-drying conditions and postdrying storage time and temperature on Salmonella choleraesuis and Salmonella typhimurium survival when inoculated in liquid porcine plasma.

The objective of this study was to determine the effectiveness of the spray-drying process on the inactivation of Salmonella choleraesuis and Salmonella typhimurium spiked in liquid porcine plasma and to test the additive effect of immediate postdrying storage. Commercial spray-dried porcine plasma was sterilized by irradiation and then reconstituted (1:9) with sterile water. Aliquots of reconstituted plasma were inoculated with either S. choleraesuis or S. typhimurium, subjected to spray-drying at an inlet temperature of 200°C and an outlet temperature of either 71 or 80°C, and each spray-drying temperature combinations were subjected to either 0, 30 or 60 s of residence time (RT) as a simulation of residence time typical of commercial dryers. Spray-dried samples were stored at either 4·0 ± 3·0°C or 23·0 ± 0·3°C for 15 days. Bacterial counts of each Salmonella spp., were completed for all samples. For both Salmonella spp., spray-drying at both outlet temperatures reduced bacterial counts about 3 logs at RT 0 s, while there was about a 5·5 log reduction at RT 60 s. Storage of all dried samples at either 4·0 ± 3·0°C or 23·0 ± 0·3°C for 15 days eliminate all detectable bacterial counts of both Salmonella spp. SIGNIFICANCE AND IMPACT OF THE STUDY: Safety of raw materials from animal origin like spray-dried porcine plasma (SDPP) may be a concern for the swine industry. Spray-drying process and postdrying storage are good inactivation steps to reduce the bacterial load of Salmonella choleraesuis and Salmonella typhimurium. For both Salmonella spp., spray-drying at 71°C or 80°C outlet temperatures reduced bacterial counts about 3 log at residence time (RT) 0 s, while there was about a 5.5 log reduction at RT 60 s. Storage of all dried samples at either 4.0 ± 3.0°C or 23.0 ± 0.3°C for 15 days was effective for eliminating detectable bacterial counts of both Salmonella spp.

Evaluation of ultraviolet-C and spray-drying processes as two independent inactivation steps on enterotoxigenic Escherichia coli K88 and K99 strains inoculated in fresh unconcentrated porcine plasma.

The objectives of this study were to assess the effectiveness of an ultraviolet (UV-C, 254 nm) irradiation system and the spray-drying method as two independent safety steps on inactivation of Escherichia coli K88 and K99 spiked in porcine plasma at 6·46 ± 0·04 log10  ml-1 and 6·78 ± 0·67 log10  ml-1 respectively for UV-C method, and at 7·31 ± 0·39 log10  ml-1 and 7·66 ± 0·11 log10  ml-1 , respectively for the spray-drying method. The UV-C method was performed at different UV light doses (from 750 to 9000 J l-1 ) using a pilot plant UV-C device working under turbulent flow. Spray-drying treatment was done at inlet temperature 220 ± 1°C and two different outlet temperatures, 80 ± 1°C or 70 ± 1°C. Results indicated that UV-C treatment induced a 4 log10 viability reduction for both E. coli at 3000 J l-1 . Full inactivation of both E. coli strains was achieved in all spray-dried samples dehydrated at both outlet temperatures. The special UV-C system design for turbid liquid porcine plasma is a novel treatment that can provide an additional redundant biosafety feature that can be incorporated into the manufacturing process for spray-dried animal plasma. SIGNIFICANCE AND IMPACT OF THE STUDY: The safety of raw materials from animal origin such as spray-dried porcine plasma (SDPP) may be a concern for the swine industry. Ultraviolet treatment at 254 nm (UV-C) of liquid plasma has been proposed as an additional biosafety feature in the manufacturing process of SDPP. We found that UV-C exposure in the liquid plasma at 3000 J l-1 reduces about 4 log10 ml-1 for E. coli K88 and K99. Full inactivation of both E. coli strains was achieved in all spray-dried samples. The incorporation of UV-C treatment to liquid plasma improves the robustness of the SDPP manufacturing process.

Analytical and Clinical Evaluation of the PathoNostics AsperGenius Assay for Detection of Invasive Aspergillosis and Resistance to Azole Antifungal Drugs Directly from Plasma Samples.

With the proposal to include Aspergillus PCR in the revised European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) definitions for fungal disease, commercially manufactured assays may be required to provide standardization and accessibility. The PathoNostics AsperGenius assay represents one such test that has the ability to detect a range of Aspergillus species as well as azole resistance in Aspergillus fumigatus Its performance has been validated on bronchoalveolar lavage (BAL) fluid and serum specimens, but recent evidence suggests that testing of plasma may have enhanced sensitivity over that with serum. We decided to evaluate the analytical and clinical performances of the PathoNostics AsperGenius assay for testing of plasma. For the analytical evaluations, plasma was spiked with various concentrations of Aspergillus genomic DNA before extraction following international recommendations, using two automated platforms. For the clinical study, 211 samples from 10 proven/probable invasive aspergillosis (IA) and 2 possible IA cases and 27 controls were tested. The limits of detection for testing of DNA extracted using the bioMérieux EasyMag and Qiagen EZ1 extractors were 5 and 10 genomes/0.5-ml sample, respectively. In the clinical study, true positivity was significantly greater than false positivity (P < 0.0001). The sensitivity and specificity obtained using a single positive result as significant were 80% and 77.8%, respectively. If multiple samples were required to be positive, specificity was increased to 100%, albeit sensitivity was reduced to 50%. The AsperGenius assay provided good clinical performance, but the predicted improvement of testing with plasma was not seen, possibly as a result of target degradation attributed to sample storage. Prospective testing is required to determine the clinical utility of this assay, particularly for the diagnosis of azole-resistant disease.

Storage medium of platelet transfusions and the risk of transfusion-transmitted bacterial infections.

BACKGROUND: Transfusion-transmitted bacterial infections (TTBIs) are among the most concerning risks of transfusion of platelet (PLT) concentrates. Storage medium influences bacterial growth dynamics and thereby the sensitivity of screening tests for bacterial contamination. STUDY DESIGN AND METHODS: The aim of this study was to quantify the association of storage media with the incidence of TTBIs after transfusion of PLT concentrates. In the Netherlands, the choice of storage medium is determined solely by geographic location of the hospital. We compared types of storage medium of all reported cases of TTBIs after transfusion of a PLT concentrate with types of storage medium of all produced PLT concentrates in the Netherlands from 2003 to 2014. RESULTS: Fourteen cases of TTBIs were reported, of which 57.1% received a PLT concentrate stored in PLT additive solution (PAS) and 42.9% a PLT concentrate stored in plasma. Of all produced PLT concentrates 22.3% were stored in PAS and 77.7% in plasma. The relative risk of TTBI after transfusion of a PAS-stored PLT concentrate was 4.63 (95% confidence interval [CI], 1.4-16.2) compared to transfusion of a plasma-stored PLT concentrate. The incidence of TTBIs was 22.2 per million (95% CI, 12.1-37.2 per million) transfused buffy coat PLT concentrates. CONCLUSION: Transfusion of PAS-stored PLT concentrates is associated with a fourfold increased incidence of TTBIs, compared to plasma-stored PLT concentrates.

Metagenomics analysis of red blood cell and fresh-frozen plasma units.

BACKGROUND: Although the risk of transmitting infectious agents by blood transfusion is dramatically reduced after donor selection, leukoreduction, and laboratory testing, some could still be present in donor's blood. A description of metagenomes in blood products eligible for transfusion represents relevant information to evaluate the risk of pathogen transmission by transfusion. STUDY DESIGN AND METHODS: Detection of viruses, bacteria, and fungi genomes was made by high-throughput sequencing (HTS) of 600 manufactured blood products eligible for transfusion: 300 red blood cell (RBC) and 300 fresh-frozen plasma (FFP) units. RESULTS: Anelloviruses and human pegivirus, frequent in the blood of healthy individuals, were found. Human papillomavirus type 27 and Merkel cell polyomavirus, present on the skin, were also detected. Unexpectedly, astrovirus MLB2 was identified and characterized in a FFP unit. The presence of astrovirus MLB2 was confirmed in donor's blood and corresponded to an asymptomatic acute viremia. Sequences of bacteria and fungi were also detected; they are likely the result of environmental contamination. CONCLUSION: This study demonstrates that HTS is a promising tool for detecting common and less frequent infectious pathogens in blood products.

International, prospective haemovigilance study on methylene blue-treated plasma.

BACKGROUND AND OBJECTIVES: Methylene blue is a phenothiazine dye, which in combination with visible light has virucidal and bactericidal properties, disrupting the replication of a broad range of enveloped viruses and some non-enveloped viruses. The study objective was to collect data on adverse reactions occurring with methylene blue plasma administered in a routine clinical practice environment and document their characteristics and severity. MATERIALS AND METHODS: This was an open label, multicentre, non-controlled, non-randomized, non-interventional study. Patients who receive a methylene blue plasma transfusion were observed for any signs and symptoms (adverse reactions) within 24 h safter the start of the transfusion, in different hospitals for a study duration of at least 1 year. RESULTS: A total of 19 315 methylene blue plasma units were transfused. There were eight patients with adverse reactions recorded during the study, one of them serious. Two had more than one reaction (two and four, respectively). Three patients had previous transfusions with methylene blue plasma only. CONCLUSION: Methylene blue plasma has a very acceptable safety profile with a rate of serious adverse reactions of 0·5/10 000 units.

In Vitro Dialysis of Cytokine-Rich Plasma With High and Medium Cut-Off Membranes Reduces Its Procalcific Activity.

Recently developed high-flux (HF) dialysis membranes with extended permeability provide better clearance of middle-sized molecules such as interleukins (ILs). Whether this modulation of inflammation influences the procalcific effects of septic plasma on vascular smooth muscle cells (VSMCs) is not known. To assess the effects of high cut-off (HCO) and medium cut-off (MCO) membranes on microinflammation and in vitro vascular calcification we developed a miniature dialysis model. Plasma samples from lipopolysaccharide-spiked blood were dialyzed with HF, HCO, and MCO membranes in an in vitro miniature dialysis model. Afterwards, IL-6 concentrations were determined in dialysate and plasma. Calcifying VSMCs were incubated with dialyzed plasma samples and vascular calcification was assessed. Osteopontin (OPN) and matrix Gla protein (MGP) were measured in VSMC supernatants. IL-6 plasma concentrations were markedly lower with HCO and MCO dialysis. VSMC calcification was significantly lower after incubation with MCO- and HCO-serum compared to HF plasma. MGP and OPN levels in supernatants were significantly lower in the MCO but not in the HCO group compared to HF. In vitro dialysis of cytokine-enriched plasma samples with MCO and HCO membranes reduces IL-6 levels. The induction of vascular calcification by cytokine-enriched plasma is reduced after HCO and MCO dialysis.